Superregenerative receiver



H. A. WHEELER SUPER REGENERATIVE RECEIVER Jan. 28, 1947.

Filed Feb. 11, 1944 ascnr'lsa AMPLIFIER FIG.2

: mpunen PULSE GENERATOR FIG.4

:ented Jan. 28, 1941 SUPERREGENERATIVE RECEIVER' Harold A. Wheeler, Great Neck, N. Y., assignor, by mesne assignments, to Hazeltine Research, Inc., Chicago, 111., a corporation of Illinois I Application February 11, 1944, Serial No. 521,932

This invention is directed to superregenerative eivers including an arrangement for controlan operating characteristic thereof, such as band-width or sensitivity characteristic.

i superregenerative receiver," as is well underod in the art, comprises an oscillator which aeriodically quenched at a frequency which is [on less than that of the generated oscillations d more than double the modulating frequency the signal to be received. Such a receiver I my have at least two distinct modes of operan determined largely by the operating poitials applied thereto and the quenching acn. In one, designated the linear mode, the enching action is such that the oscillations nerated in each quench cycle are quenched or mped before attaining saturation amplitude. the other, or logarithmic. mode the generated cillations are permitted to reach saturation nplitude in each quench cycle. In either case, e receiver is characterized by a high gain and e amplitude of the output signal derived therecm in any quenchcycle varies with the amitude' of the exciting signal which initiates the cillations generated in the particular quench cle. The receiver is further characterized by ie fact thatduring quiescent intervals, when a desired signals are being received, oscillations re initiated by the noise signals present in the :ceiver circuit, resulting in an output signal of alatively 10w amplitude. Such a receiver is sub- :ct to a wide range of applications and, in the sual case, either of the above-described modes f operation .may be utilized. However, in any istallation it may be desirable to provide a concol arrangement for controlling the receiver and-width or sensitivity characteristic, or both, with variations in operating conditions.

Arrangements, for controlling the operating haracteristics of a receiver are known in the .rt but are generally directly coupled to circuit vlements included within the signal-translating hannel of the receiver. For example, in order to obtain a band-Width control, it has been pro- )osed to utilize a control arrangement directly :oupled to an adjustable selector system included n the signal-translating channel and effective, n some cases, to adjust the band-pass charactervstic of the selector system in accordance with ;he intensity of received desiredsignals. Addizionally, it has been proposed to use an automatic 17 Claims. ('01. 250-20) satisfactory, in some installations itImay be desirable effectively to isolate the control arrange ment from the signal-translating channel of the volume control or A. V. C. system directly coupled to one or more'signal-translating stages of the receiver for the purpose of obtaining a sensitivity control. While these arrangements are generally receiver. This is especially,true in receivers of the superregenerative type where optimum oper ating conditions are obtained through such an isolation, as will be described presently.

Prior art control arrangements designed specifically for application to superregenerative receivers generally comprise a system which rectifies a selected portion of the receiver output signal .to generate a control voltage which is applied as a bias voltage to the oscillator tube of the receiver. The biasing circuit usually includes a high-impedance resistor provided to minimize power dissipation in the circuit. However, it is found that this high-impedance resistor has a tendency .to develop excessive bias voltages during periods of oscillation and intermittently block the receiver circuit. In some installations this tendency towards blocking may be objectionable.

The invention proposes a new type of control system which is peculiarly adapted to superregenerative receivers in which the characteristic quenching action is provided by a periodic quench voltage. The new arrangement takes advantage of the fact that variations in the amplitude or frequency characteristics of the quench voltage produce corresponding variations in the bandwidth and sensitivity characteristics of the receiver and accomplish the desired control by suitably varying either, or both, of the amplitude and frequency characteristics of the quench voltage. This arrangement presents decided advantages over those of the prior art referred to above. In the first place, when utilized as a sensitivity control, it may be arranged to obviate the undesirable blocking tendency, referred to above, which is inherent in certain prior art arrangements. Furthermore, it affords a bandwidth control which is less complicated. and expensive than those of the prior art.

It is an object of the invention, therefore, to

provide an improved control arrangement for controlling an operating characteristic of a su- -perregenerative receiver and which avoids one or more of the above-mentioned limitations of prior art arrangements;

It is another object of the invention to provide an improved control arrangement for controlling an operating .characteristic of a superregenerafive-receiver through a control of the receiver quenching action.

It is still another object of the invention to provide an improved control arrangement for a superregenerative receiver which is eifectively isolated. from the signal-translating portions thereof.

In accordance with-the invention, a superregenerative receiver including an arrangement for controlling a predetermined operating characteristic thereof comprises a regenerative oscillatory circuit and means for supplying to the oscillatory circuit a periodic quench voltage providing superregeneration and, having a characteristic which is effective to determine the above-,mentioned operating characteristic of the receiver.

The receiver includes means for deriving a signal having a characteristic which varies with an operating condition of .the receiver and means responsive to this signal for deriving a control eii'ect. Additionally, the receiver has means for utilizing the control effect to adjust the characteristic of the quench voltageso as to control the aforesaid operating characteristic of the receiver.

For a better understanding of the present invention, together with other and further objects thereof, reference is had .to the following description taken in connection with the accompanying drawing, and its scope will be pointed out in the appended claims.

In the drawing, Fig. 1 is a schematic representation of a superregenerative receiver embodying the present invention; Fig. 2 comprises graphs which illustrate alternative operating characteristics of a portion of the Fig. l arrangement; Fig. 3 is a schematic representation of a superregenerative receiver embodying the invention in modified form; while Fig. 4 is a schematic circuit diagram of a wave-signal transpondor system including the invention.

Referring now more particularly to Fig. 1, the superregenerative receiver there represented has a linear mode of operation and comprises a regenerative oscillatory circuit including a vacuum tube 10 and a frequency-determining circuit provided by a variable inductor II and a condenser C. Condenser O is shown inbroken-line construction since it may be comprised in whole, or in part, of the distributed capacitance of inductor and the interelectrode capacitance of the anode and control electrodes of tube III. The frequency-determining circuit is coupledto the anode of tube Ill through a coupling condenser l2 and has a direct wire connection to the control electrode thereof, the mid-tap of inductor I I and the cathode of tube In being grounded to complete the regenerative oscillatory circuit. There is also coupled to the anode and cathode of tube l means for supplying to the regenerative circuit a periodic quench voltage, providing superregen-' eration and having a characteristic which is effective to determine a predetermined operating characteristic of the receiver. This means comprises a radio-frequency choke l3 and the sec-' ondary winding of an iron-core transformer I4,

by-passed for radio-frequency currents by a condenser IS. The primary winding of transformer I4 is damped by a resistor l3 and constitutes the load circuit of a pentagrid tube I I. The cathode, first and second control electrodes of tube ll function, respectively, as the cathode, control electrode and anode of a quench-frequency oscillation generator l8 which produces a periodic quench voltage of rectangular wave form and of a frequency which is low with reference to the operating frequency of the regenerative oscillatory circuit but high with reference to the modulating frequencies of the signals to be received. Oscillation generator I8 is of the well- 4 known tuned-plate type having a tuned circuit including an inductor l9\and a condenser 20 coupled to its anode electrode. In the control electrode-cathode circuit of generator [8 there are a grid-stabilizing resistor 2|, an inductor 22 inductively coupled with inductor l9 and a biasing arrangement comprising the parallel combination of a condenser 23 and a resistor 24. Operating potentials are applied to tube I! from sources of space current indicated +3 and +Sc.

The superregenerative receiver also includes means, specifically a detector system, for deriving from the regenerative oscillatory circuit an output signal having an amplitude characteristic determined by the operating conditions of the receiver. The detector system consists of a diode detector 30 coupled to the frequency-determining circuit of the receiver'through a coupling condenser 3l and having as a load circuit a radiofrequency choke 32 and a resistor 33, by-passed for radio-frequency currents by a condenser 34.

The output signal of the detector may be supplied to any suitable utilizing circuit, as indicated by the arrow 35. This output signal is also supplied to a unit 40, comprising means responsive thereto for deriving a control effect. Unit 40 includes an amplifier 4| of one or more stages having an input circuit coupled to resistor 33 and having one or more selector circuits arrangedto have a pass-band characteristic, as represented by curve a of Fig. 2. From this curve it will be apparent .that the amplifier has amaximum response to applied signal components which have a frequency j corresponding to the quenching frequency of the receiver, that is, the frequency of the applied quench voltage. To the output circuit of amplifier 4| is coupled a rectifier 42 of conventional construction. A control effect or voltage of negative polarity is derived in the output circuit of rectifier 42 and applied to a control electrode of pentagrid tube II, this control electrode providing means for utilizing the control effect to adjust a characteristic of the quench voltage so as to control an operating characteristic of the receiver. An antenna-ground system 50 is provided for the receiver and is coupled to the frequency-determining circuit thereof by way of an inductor 5|.

In considering .the operation of the described receiver. it will be assumed initially that no signals are intercepted by antenna system 50. For this no-signal or quiescent operating condition, the receiver has predetermined band-width and sensitivity characteristics determined largely by the amplitude and frequency characteristics of th applied'quench voltage, but also determined by such factors as 'the characteristics of vacuum tube Ill and its associated frequency-determining circuit. Oscillations are periodically produced in the receiver circuit under the influence of the applied quench voltage in accordance with the characteristic operation of a superregenerative circuit. These oscillations have a frequency corresponding to the operating frequency of the regenerative oscillatory circuit and a relatively low amplitude as determined by the operating characteristics of the receiver and the receiver noise signals which, for the quiescent condition under consideration, initiatev the oscillations in successive quench cycles; The generated oscillations are detected by detector 30, producing across resistor 33 a low-amplitude periodic-signal voltage.

voltage and includes components harmonically related to the quench frequency, as I ponents corresponding to the noise signals of the receiver circuit. The quenchdrequency component thereof is translated through amplifier 4| and rectifier 42 of unit 40, producing in the output circuit of rectifier 42 a control voltage having a magnitude determined by the amplitude of the quiescent signal output of the receiver. The control voltage is applied with negative polarity to a control electrode of pentagrid tube H to control the trans-conductance thereof and determine the amplitude of the applied quench voltage.

The circuit arrangements of unit 40 are ad- Justed so that under normal conditions of operation the amplitude of the applied quench voltage is such as to establish a predetermined band width and optimum sensitivity of the receiver. If a change in the operating conditions of the receiver causes the amplitude of the quiescent signal output thereof to be increased, indicating an increased sensitivity, the signal input to unit 40 is increased proportionately and results in a similar increase in the negative-polarity control voltage obtained from rectifier 42. This increase in the control voltage as applied to pentagrid tube l1 reduces the amplitude of the applied. quench voltage so as torestore the sensitivity of the receiver to the desiredoptimum value. Conversely, a decrease in the amplitude oflthe quiescent slg nal output reduces the magnitude of the control voltage and increases the amplitude of theapplied quench voltage to restore optimum sensitivity. Thus, with the described arrangement, the sensitivity characteristic of the'receiver is maintained at a desired level through a control of the amplitude characteristic of the quench voltage. The band-width characteristic of the receiver, which varies directly with variations in the amplitude of the quench voltage, may not be maintained constant in this arrangement since the amplitude of the quench voltage is adjusted to compensate for any change in operating. conditions which causes the quiescent signal output of the receiver to deviate from a desired signal level.

Now it will be assumed that a pulse-modulated radio-frequency signal is intercepted by antenna system ill. In general, this signal will have a. high intensity with referenceto the noise signals. in the receiver circuit so that the oscillations gen-- erated in each quench cycle occurring within the duration of a received pulse have a relatively high amplitude. During the intervals which intervene between pulses of the .receivedsignal, the output signal of detector 30 comprises the low-amplitude quiescent signal described above. The resulting output signal of the receiver, including both the high-amplitude and low amplitude signal components, is supplied tothe utilizing circuit which well as comacteristic, as represented by curve 12 of Fig. 2, in installations where the receiver is to receive pulsemodulated signals. In, such a case, unit 40 reiects the quench-frequency components of the quiescent signal output of the receiver and derives the desired control voltage in response to the noise-signal components or the quiescent signal.

The operation of unit 40 in utilizing these signal I components to control the band-width and sensitivity characteristics of the receiver is substantially as described above.

In the reception of continuous-wave signals it is advantageous to include selector circuits in unit 40 which have a pass-band characteristic as represented by curve a of Fig. 2. In this case, the v control arrangement functions in a manner analogous to automatic volume control arrangements .to maintain the signal output of detector 30 within a relatively narrow-amplitude range for a wide range of received signal amplitudes.

The control circuits in the Fig. 1 arrangement are efl'ectively isolated from the signal-translating portions of, the receiver which, as'pointed out above, is especially desirable for receivers of the superregenerative type. Additionally, the coupling circuits which couple tube III to the frequency-determining circuit and through which the quench voltage is applied to the regenerative circuit have an impedance which is substantially lower than the impedance of vacuum tube I0 at frequencies less than that of the quench voltage. This also is a particularly desirable feature inas-.- much as it obviates the undesirable blocking tendency of certain prior art receiver circuits, mentioned above, which include a high-impedance bias resistor in the control electrode-cathode circuit of the oscillator tube.

The arrangement of Fig. 3 represents a superregenerative receiver which is generally similar to thatof Fig. l, but includes a modified control arrangement in accordance with the invention which is more flexible than that of Fig. 1. Corresponding elements of these receivers are identified by'like reference numerals primed. The control arrangement of Fig. 3 comprises a capacitivetype reactance-tube circuit for controlling the op-v crating frequency of the quench-frequency oscilmay include suitable means, such as an ampli- Y tude-selective arrangement, for responding only to the high-amplitude components which correspond .to the pulses" of the received signal. This output signal is also appliediounit 4|} for controlling the operating characteristics of, the receiver. However, where thequenching frequency v, is very high with reference to that of the modulating frequency of the received signal, the highamplitude component's v appear at such a low repetition frequency as to have substantially no eifect on the control voltage derived in unit 40 which later it, thereby to control the frequency characteristic of the generated quench, voltage. This circuit includes a vacuum tube 25 having an output circuit which is coupled to the anodecathode circuit of generator IS. A condenser 26 provides a capacitive feed-back path between the anode and control electrodes of tube 25. An in- ,ductor 21 and shunt-connected resistor 28 are included'in the control electrode-cathode circuit of tube 25 so that the feed-back voltage has a quadrature-phase relation with reference to that of the anode-cathode circuit voltage. the load circuit of rectifier 42' includedin unit 40' comprises a pair of parallel voltage-dividing resistors 43 and 44, center tapped to ground so that control voltages of opposite polarities may be obtained from .each. For convenience of explanation, the polarity of the control voltages with reference to ground is indicated on the drawing. A voltage tap." associ'ated'with resistor 43 derives one control voltage whichis applied to the reactance tube 25 to control the operating frequency of oscillator I8. A similar tap 46 assO- ciated with resistor 44 derives a second control voltage which is applied to a control electrode of pentagrid tube II, as in the Fig. I arrange- Additionally,

ment, to control the amplitude of the quench voltage.

In considering the operation of the control arrangement of Fig. 3, it will be assumed that no signals are intercepted by antenna 50. Unit 48' selects a portion ofthe quiescent signal output of the receiver which is rectified in rectifier 42, producing control voltages across resistors 43 and 44. Taps 45 and 46 select control voltages for application to reactance tube 25 and pentagrid tube II, respectively, to control the operating characteristics of the receiver by varying the frequency and amplitude characteristics of the quench voltage. Taps 45 and 48 are adjusted so as to effect predetermined relative variations of the band-width and sensitivity characteristics of" the receiver with variations in amplitude of the quiescent signal output. The adjustments of these taps may be determined from the following considerations.

It may be shown that like variations in the amplitude and frequency of the quench voltage are eifective to vary the band-width characteristic of the receiver in the same sense, but they vary the sensitivity characteristic thereof in opposite senses. More specifically, an increase in either the amplitude or the frequency of the quench voltage causes the receiver to have a greater band width, but an increase in the amplitude of the quench voltage increases the receiver sensitivity, while an increase in the frequency decreases the sensitivity. Therefore, through suitable adjustments of taps 45 and 46, control voltages may be derived from unit of such relative magnitudes and polarities as to efi'ect any desired relative variation of the receiver band-width and sensitivity characteristics with variations in amplitude of the quiescent.

signal output. For example, the band width may be maintained substantially constant by adjusting taps and 46 so that an increase in the amplitude of the quiescent signal output produces a. decrease in the amplitude of thequench voltage and a related increase in the frequency of the quench voltage.

In the reception of pulse-modulated or continuous-wave signals the receiver of Fig. 3 operates in a manner similar to that of the receiver represented in Fig. 1. This operation will be apparent from the foregoing description.

In Fig. 4 there is represented a wave-signal transpondor system including a receiver constructed in accordance with the teaching of the present invention. As used in this specification, the term transpondor system is intended to describe a wave-signal translating system which includes a receiver and a transmitter so arranged that a predetermined answer or reply signal is transmitted in response to a received interrogating signal, thereply and interrogating signals preferably comprising radiant-energy wave signals. For convenience of explanation, the system is illustrated as a radio beacon for transmitting direction-finding information to interrogating aircraft. The receiver portion of the transpondor system consists of a superregenerative'receiver having a linear mode of operation. This receiver comprises a vacuum tube 80 and a frequency-determining circuit provided by a variable inductor 8| and ..a condenser C. Coni denser C is shown in broken-line construction since it may be comprised in whole, or in part, of the distributed capacitance of inductor 8| and the interelectrode capacitance of the anode and control electrodes of tube 80. The frequency-determining circuit is damped by a resistor 82 and is coupled to the anode and control electrodes of tube 80 by way of coupling condensers 68 and 84. respectively. The cathode circuit of tube 80 includes a radio-frequency choke 85 and a resistor 66. A biasing circuit is coupled to the control electrode thereof, including a radio-frequency choke 81, a resistor 68 and a source of bias voltage indicated C. A source of space current indicated +B is coupled to the anode of tube 60 through a radio-frequency choke 19 and a quench voltage providing superregeneration is applied thereto from a quench-frequency oscillator 69 by way of vacuum-tube amplifier ll coupled to oscillator 89 through a coupling condenser 10. The load circuit of amplifier II consists of a tuned circuit, including an inductor I2 and a condenser 13, tuned to the frequency of the quench voltage and highly damped by a resistor 14. A coupling condenser 89 couples the load circuit of amplifier H to the control electrode of tube 80.

A detector 15. for deriving an output signal from the regenerative oscillatory circuit is coupled thereto through a condenser 18. The load circuit of detector 15 comprises a radio-fre quency choke I1 and a resistor 18. A control arrangement 88 is coupled to the load circuit of detector 15 and includes an amplifier 8| of one or more stages having an output circuit coupled to a diode rectifier 82 through a coupling condenser 83. Rectifier 82 has a load circuit including a resistor 84 and a control voltage derived therefrom-is applied through a resistor 85 to the. control electrode of vacuum tube amplifier II for the purpose of controlling the amplitude characteristic of the quench voltage in accordance with variations'in amplitude of the output signal of detector 15, thereby to determine and control the sensitivity and band-width characteristics of the receiver. An antenna system 88 is capacitively coupled to the regenerative oscillatory circuit through a condenser 88 and is inductively coupled thereto .by means of an inductor 81.

The transmitter portion of the transpondor system likewise comprises a, regenerative oscillatory circuit including a vacuum tube 98 having anode and control electrodes which are coupled through condensers 9| and 81. respectively, to the above-described frequency-determining 'circuilw which is common to both the receiver and transmitter units. The cathode circuit of tube 88. in-

cludes a radio-frequency choke 88 and a timeconstant circuit provided by the parallel arrangement of a condenser 84 and resistor 95. A- source of bias voltage C is applied to the control electrode of tube 88 through a radio-frequency choke 98 and is selected of such magnitude as normally to block oscillations in the transmitter.

A pulse generator 91, having an input circuit coupled to'load resistor-18' of detector 15 and having an output circuit coupled to the anode of transmitting tube through a radio-frequency choke 98, permits control of the transmitter operation under the influence of the receiver, as described more particularly hereinafter. Generator 9! may comprise a conventional trigger circuit such as a single-pulse relaxation oscillator which,-when keyed, generates a single pulse of unidirectional potential having a substantially rectangular wave form.

In considering the operation of the described transpondor system, it will be assumed initially that no signals are being intercepted by the antenna system 88. For the assumed operating conditions, the quiescent signal output of the receiver is'detected in detector 15 and applied to v 9 Y unit for thepurpose of developing acontrol voltage having a magnitude which varies in accordance with the amplitude variations of the quiescent signal output of the receiver. This control voltage is appliedto amplifier II to control the amplitude characteristic of the applied 01' both the sensitivity and band-width characteristics of the receiver in themanner fully described above. The quiescent signal output of the quench voltage so as to effect a desired control receiver is also applied to generator 91. However,

this output signal, which has plow-amplitude Serial No. 521,926, filed concurrently with this transpondor transmits thereto an interrogating signal comprising a pulse-modulated radio-frequency signal. As indicated above, an output signal of relatively high amplitude is derived in the U load circuit of detector H5 in quench cycles occurring within the interval of the received pulse of the interrogating signal. This high-amplitude signal keys generator 91 for a single cycle and applies a pulse of unidirectional potential to the anode-cathode circuit of tube 90 of sufllcient magnitude to overcome the normal holding voltage applied to the control electrode thereof and initiate oscillations in the transmitter. As the oscillations of tube 90 continue, condenser 94 included in its cathode circuit becomes charged, raising the cathode potential thereof; tending to terminate transmission. The value of condenser 94 is so chosen that the transmitted pulse generated by tube 90 and transmitted through the common antenna system 88 has a predetermined pulse duration, preferably equal tothat of the received pulses of the interrogating signal. Thus, in response to a received interrogating signal, the

. 1o may-be developed from the signal output of an amplifier stage intermediate the antenna system and the regenerative circuit, or from the signal output of an auxiliary antenna system. In any case, the control voltage is to be derived from a signal having a characteristic which varies with an operating condition of the receiver,

It will also be understood that units l0, l0 and 80 may include arrangements which permit the receiver to translate pulse-modulated received signals having pulse-repetition frequencies-that vary over a wide frequency range. One such arrangement is disclosed in copending application application, in the name of John A. Hansen and Bernard D. Loughlin and assigned to the same assignee as the first invention.

The receiver circuits described above have a linear mode of operation but may operate with a logarithmic'mode if desired. In such a case. an integrating circuit may be included for deriving an output signal having a characteristic, such as an amplitude characteristic, which is determined by the operating characteristics of the receiver. It will be apparent that the teaching of the invention is equally, applicable to such receiver While there have been described what are at present considered to be the preferred embodiments of this inventiomit will be obvious to those skilled in the art that various changes and modifications may be made therein without departing transponder system transmits a reply signal comprising pulses of radio-frequency energy having the same duration and pulse-repetition frequency as the received signal. The inquiring aircraft is able to obtain bearing indications from the transmitted signal or. if desired. the transmitted signal may be coded to transmitdesired directionfinding information. Suitable coding arrangements for this purpose are fully disclosed in copending application Serial No. 516,394. filed December 31. 1943. in the name ofBernard D.

I Loughlin and assigned to thesame assignee as the present invention.

-In the arrangements described above, the

quench voltage has been defined as having a substantially rectangularwave form. It will be understood that other wave forms may be utilized if desired. For example, quench voltages of si'- ,nusoidal wave form are commonly employed in the art. Likewise, in controlling a characteristic of the quench voltage, it is not necessary that the described control arrangement be adjusted to from the invention, and it is, therefore, aimed in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the invention.

What is claimed'is:

l. A superregenerative receiver including an arrangement for controlling a predetermined operating characteristic thereof comprising, a regenerative oscillatory circuit, means for supplying to said circuit a periodic quench voltage providing superregeneration and having a characteristic effective to determine said operating characteristic of said receiver, means for deriving a signal having a characteristic varying with an op- .erating'condition of said receiver, means responsive to said signal for deriving a control effect, and means for utilizing said control effect to adjust said,:characteristic of said quench voltage so asto control said operating characteristic of said receiver.

a 2. A s'uperregenerative receiver including an.

. arrangement for controlling a predetermined opcrating characteristic thereof comprising, a rea generative oscillatory circuit, means for supplying maintain a given sensitivity in the receiver. As

indicated above, the control feature may be utilized to maintain a given band width or, through the use of the Fig. 3 control arrangement. 'a desired relative control of bandwidth and sensitivity may be obtained. Also, the control voltage the output signal of the regenerativ oscillatory circuit. For example, in utilizing the control 9.1-

to said circuit a periodic quench voltage providing 1 superregeneration and having a characteristic effective to determine said operating characteristic of saidreceiver, means for deriving from said circuit anoutput signal having a characteristic determined by said operating characteristic of said receiver, means responsive to said output signal for deriving a. control effect, and means for utilizing said control effect to adjust said characteristic of said quench voltage so as to control said operating characteristic of said receiver.

need not necessarily be derived in response to I rangement primarily tocontrol the band width of the receiver, the control voltage may be de-' rived in response to the intensity of a received desired signal. In such a case, the control voltage 3. A superregenerative receiver including an arrangement for controlling a predetermined operating characteristic thereof comprising. a regenerative oscillatory circuit, means for supplying to said circuit a periodic quench voltage providing superregeneration and having a characteristic effective to determine said operating characteristic of said receiver, means for deriving a 11 'signal having an amplitude characteristic varyin with an operating condition of said receiver, means responsive to the amplitude of said signal for deriving a control eflect, and means for utiliz- 1 ing said control efiect to adjust said characteristic of said quench voltage so as to cohtrol said operating characteristic of said receiver.

4. A superregenerative receiver including an arrangement for controlling predetermined operating characteristic thereof comprising, a regenerative oscillatory circuit, means for supplying to said circuit a periodic quench voltag providing superregeneration and having a characteristic effective to determine said operating-characteristic'of said receiver, means for deriving a signal having an amplitude characteristic varying with an operating condition of .said receiver, means for detecting the amplitude of said signal to derive a control eiiect, and means for utilizing said control eilect to adjust said characteristic of said quench voltage so as to control said operating characteristic of said receiver.

5. A superregenerative receiver including an arrangement for controlling a predetermined op- "erating characteristic thereof comprising, a regenerative oscillatory circuit, means for supplying to-said circuit a periodic quench voltage providing superregeneration and having an amplitude characteristic eflectiveto determine said operating characteristic of said receiver, means for deriving a signal having a characteristic varying with an operating condition of said receiver, means responsive to said signal for deriving a control effect, and means for utilizin sai control eii'ect to adjust saidv amplitude characteristic of said quench voltage so as to control said operating characteristic of said receiver.

' 6. A superregenerative receiver including an arrangement for controlling a predetermined operating characteristic thereof comprising, a regenerative oscillatory circuit, means for supplying to said circuit a periodic quench voltageprovid- I ing superregeneration and having a frequency characteristic effective to determine said operating characteristic of said receiver, means for deriving a signal having a characteristic varying with an operating condition of said receiver, means responsive to said signal for deriving a con-, trol effect, and means for utilizing said control effect to adjust said frequencycharacteristic of said quench voltage so as to control 7 said operatingcharacteristic of said receiver.

7. A superregenerative receiver including an arrangement for controlling the band-width and sensitivity'characteristics thereof comprising, a regenerative oscillatory circuit, means for supplying to said circuit a periodic quench voltage providing superregeneration and having a characteristic effective to determine said band-width and sensitivity characteristics of said receiver, means for deriving a signalhaving a'characteristic varying with an operating condition of said receiver, means responsive to said signal for deriving a control effect, and means for utilizingsaid control eii'ect to adjust said characteristic of said quench voltage so as to control said band width and sensivitity characteristics of said receiver.

8. A superregenerative receiver including an arrangement for controlling a predetermined operating characteristic thereof comprising, a regenerative oscillatory circuit, means for supplying to said circuit a periodic quench voltage providing superregeneration and having amplitude and f quency characteristics which are individualiy effective to control said operating characteristic of said receiver, means for deriving a signal having a characteristic varying with an operating condition of said receiver, means responsive to said signal for deriving a control eiiect, and means for utilizing said control eflect individually to control said amplitude and frequency characteristics of said quench voltage so as to control said operating characteristic of said receiver. .9.;A superregenerative receiver including an arrangement for controlling the band-width and sensitivity characteristics thereof comprising, a regenerative oscillatory circuit, means for supplying to said circuit a periodic quench voltage 15 providing superregeneration and having amplitude and frequency characteristics which control said band-width characteristic of said receiver in the same sense and which control said sensitivity chargcteristic thereof in opposed senses, means for eriving a signal having a characteristic varying with an operating condition of said receiver, means responsive to said signal for deriving a control eflect, and means for utilizing said control effect individually to control said arrangement for controlling the band-width and sensitivitycharacterlstics thereof comprising, a

regenerative oscillatory circuit, means for supplying to, said circuit a periodic quench voltage providing superregeneration and having amplitude and frequency characteristics which control said band width of said receiver in the same sense and which control said sensitivity characteristic thereof in opposed senses, means for deriving a signal having a characteristic varying with an operating condition of said receiver, means re- 40 sponsive to said signal for deriving a control effect having a magnitude determined by said characteristic of said signal, and means for utilizing said control effect individually to control said amplitude and frequency characteristics of said quench voltage so as to vary at least one of said band-width and sensitivity "characteristics of said receiver with variations of said characteristic of said signal.

11. A superregenerative receiver including an arrangement for controlling the band-width and sensitivity characteristics thereof comprising. a regenerative oscillatory circuit, means for supplying to said circuit a periodic quench voltage providing superregeneration and having ampli- 5 tude and frequency characteristics which control said band-width characteristic of said receiver in the same sense and which control said sensitivity characteristic thereof in,opposed senses, means for deriving a signal having a characteristic varying with an operating condition of said receiver, means responsive tosaid signal for de-' said receiver with variations of said characteristic of said signal.

12. A superregeuerative receiver including an arrangement for controlling the band-width and sensitivity characteristics thereof comprising. a

- regenerative oscillatory circuit, means for supplying to said circuit a periodic quench voltage ti'vity characteristic thereof in opposed 14 age as to control said operating characteristic of said receiver.

15. A superregenerative receiver including an arrangement for controlling a predetermined deriving at least two control effects individually having .a magnitude determined by said char acteristic of said signal, andmeans for utilizing one of said control eil'ects to control said amfor utilizing another of said control eifects to control said frequency characteristic of said voltage, said control effects having such relative magnitudes as to effect predetermined relative variations of said band-width and sensitivity characteristics of said receiver with variations of said characteristic of said signal.

13. A superregenerative receiver including an arrangement ifor controlling the band-width and sensitivity characteristics thereof comprising, a regenerative oscillatory circuit, means for supplying to said circuit a periodic quench voltage providing superregeneration and having amplitude and frequency characteristics which control said band-width characteristic of said receiver in the same sense and which control said sensi- I I senses. means for deriving a signal having a characteristic varying withan operating condition of said receiver, means responsive to .said signal for deriving at least two control voltages individually having a magnitude determined by said characteristic of said signal, and means for utilizing one of said control voltages to control said amplitude characteristic of said quench voltage and for utilizing another of said control voltages to control said frequency characteristic of said quench voltage, said control voltages having such relative magnitudes and polarities as to effect I predetermined relative variations of said bandwidth andsensitivity characteristics of said receiver with variations of said .characteristic 'of said signal. I a

14. A superregenerative receiver including an arrangement for controlling a predetermined operating characteristic thereof comprising, a regenerative oscillatory circuit, means including an oscillation generator for supplying to said circuit a periodic quench voltage providing superregeneration and having a characteristic effective to determine said operating characteristic of said receiver. means for derivi a signal having a characteristic varying with anoperating condition of said receiver, means responsive to said signal for deriving a control voltage, means for applying said control voltage to said generator sotovarysaidcharacteristicofsaidquenchvoltplitude characteristic of said quench voltage and operating characteristic thereof comprising, a regenerative oscillatory circuit means including an oscillation generator and a vacuum-tube amplifier for supplying to said circuit a, periodic quench voltage providing superregeneration and having an amplitude characteristic effective to determine said operating characteristic of said receiver,

means for deriving a signal having a characteristic varying with an operating condition of said receiver, means responsive to said signal for deriving a control voltage, means for applying said control voltage to said amplifier to adjust said amplitude characteristic of said quench voltage so as to control said operating characteristic of I said receiver.

16. A superregenerative receiver including an arrangement for controlling a predetermined operating characteristic thereof comprising, a regenerative oscillatory circuit, means including an oscillation generator for supplying to said circuit a periodic quench voltage providing superregeneration and having a frequency characteristic effective to determine said operating characteristic of said receiver, means for deriving a signal having a characteristic varying with an operating condition of said receiver, means responsive to said signal for deriving a control effect, and reactance-tube means for utilizing said control effeet to adjust the operating frequency of said generator so as to control said operating characteristic of said receiver.

17. ,A superregenerative receiver including an arrangement for-controlling a predetermined operating characteristic thereof comprising, a re- I generative oscillatory circuit including vacuumtube means and a frequency-determining circuit, means for supplying to said oscillatory circuit a periodic quench voltage providing superregeneration and having a characteristic effective to determine said operating characteristic of said receiver, said oscillatory circuit and said quenchvoltage supply means including only coupling circuit having an impedance which is substantially lower than the impedance of said vacuum-tube means at frequ voltage for. coup said frequency-determining circuit and for applying said quench voltage thereto, mans for deriving a signal having a characteristic varying cies less than that of said quench with an operating condition of said receiver.

means responsive to said signal for deriving a control effect, and means for utilizing said con trol effect to adjust said characteristic of said quench voltage so as to control said operating characteristicof said receiver.

HAROLD A.

g said vacuum-tube means to 

